In the fifth installment of the Saikyou Series, meet Aikawa Jun, a renowned detective known as Humanity's Strongest Contractor. Join her in a relentless mystery entwined with two captivating women and a chilling serial killer. When tasked with a field investigation alongside the young psychology prodigy Jikumoto Miyori and the flawless maid Handa Rei, what was supposed to be a leisurely journey turns sinister in Venice. As tourists and renowned actresses fall victim to a mysterious 'drowned killer,' the shadow of danger looms over these women. Will Aikawa Jun's unparalleled strength be enough to unravel the truth behind these brutal murders?